Tanikawa Motoki, Yamada Hiroshi, Sakata Tomohiro, Mase Mitsuhito
Department of Neurosurgery, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho, Nagoya, Aichi, Japan.
Surg Neurol Int. 2020 Nov 6;11:370. doi: 10.25259/SNI_439_2020. eCollection 2020.
In the treatment of giant cell tumor of bone (GCTB), the efficacy and safety of denosumab, a receptor activator nuclear factor κ-B ligand inhibitor, has previously been demonstrated, especially for unresectable tumors. One of the current issues in denosumab treatment for unresectable GCTB is whether it can be discontinued, or whether the dosage or the dosing interval can safely be adjusted, if discontinuation is not possible, to avoid the occurrence of side effects.
A 15-year-old boy with diplopia was referred to our hospital after a space-occupying lesion in the sphenoid bone was found on head CT. Partial removal of the tumor was performed through an endoscopic endonasal approach, and pathological diagnosis was confirmed as GCTB. Thereafter, the patient received 120 mg subcutaneous injections of denosumab every 28 days for the first 2 years. Since bone formation was induced and sustained along with tumor reduction, the dosing interval was gradually extended, with 4 monthly dosing for the next 1 year, followed by 6 monthly dosing for the succeeding 2 years. With the extension of the dosing interval, the ossified tumor has regrown slightly, but within an acceptable range.
Discontinuation of denosumab treatment for unresectable GCTB was not thought to be possible for the current case due to the nature of the drug, as reported in the literature. Extending the dosing interval up to 6 monthly, as could be done safely in the current case, can be considered a useful and appropriate measure.
在骨巨细胞瘤（GCTB）的治疗中，核因子κ-B受体活化因子配体抑制剂地诺单抗的疗效和安全性已得到证实，尤其是对于不可切除的肿瘤。目前，地诺单抗治疗不可切除GCTB的一个问题是是否可以停药，或者如果无法停药，为避免副作用的发生，是否可以安全调整剂量或给药间隔。
一名15岁复视男孩因头部CT发现蝶骨占位性病变转诊至我院。通过鼻内镜经鼻入路对肿瘤进行了部分切除，病理诊断为GCTB。此后，患者在最初2年每28天接受120mg地诺单抗皮下注射。由于随着肿瘤缩小诱导并维持了骨形成，给药间隔逐渐延长，接下来1年每4个月给药1次，随后2年每6个月给药1次。随着给药间隔的延长，骨化肿瘤略有复发，但在可接受范围内。
如文献报道，由于药物性质，目前该病例认为无法停用治疗不可切除GCTB的地诺单抗。如本病例安全做到的那样，将给药间隔延长至每6个月1次，可被视为一种有用且合适的措施。
